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Question
The primary coil of an ideal step-up transformer has 100 turns and the transformation ratio is also 100. The input voltage and power are 220 V and 1100 W, respectively. Calculate the
(a) number of turns in secondary
(b) current in the primary
(c) a voltage across secondary
(d) current in secondary
(e) power in secondary
Solution
(a) Number of turns in secondary coil is given by
`N_S/N_P=n`
`=>N_S/100=100`
⇒NS=10,000
(b) Current in primary is given by
IPVP=P
`=>I_P=1100/220=5A`
(c) Voltage across secondary is given by
`V_S/V_P=N_S/N_P=n`
⇒VS=100×220=22,000 V
(d) Current in secondary is given by
VSIS=P
`=>I_S=P/V_S=1100/22000=0.05A`
(e) Power in secondary is power in primary in an ideal transformer.
= 1,100 W
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